In a thermal processing apparatus ( 1 ), an upper opening ( 60 ) of a chamber body ( 6 ) is closed by a transparent plate ( 61 ) and a light emitting part ( 5 ) emits light into the chamber body ( 6 ) through the upper opening ( 60 ). Inside the chamber body ( 6 ) provided are a susceptor ( 72 ) for supporting a substrate ( 9 ), a hot plate ( 71 ) for heating the susceptor ( 72 ) and a cover member ( 21 ) disposed between the transparent plate ( 61 ) and the susceptor ( 72 ). The susceptor ( 72 ) is provided with a recessed portion whose depth is larger than the thickness of the substrate ( 9 ), and a lower surface of the substrate ( 9 ) is supported by a bottom surface of the recessed portion and a periphery of the substrate ( 9 ) is surrounded by the side wall portion of the recessed portion. During a processing for the substrate ( 9 ), the cover member ( 21 ) is moved down and brought into contact with an upper end of the side wall portion of the recessed portion to close the recessed portion. This makes it possible to easily block the periphery of the substrate ( 9 ) inside the chamber body ( 6 ), and as a result, even if the substrate ( 9 ) is broken during the processing, it is possible to prevent the pieces of the substrate from being scattered.
